#import "Common/ShaderLib/GLSLCompat.glsllib"

uniform vec4      m_Diffuse;
uniform sampler2D m_BarkMap;
uniform bool      m_HasBarkMap;

in vec2 texCoord;
in vec3 worldNormal;

void main() {
    vec3 n = normalize(worldNormal);

    // Sun at ~45° elevation from SE — good contrast on vertical cylinders
    vec3 sunDir  = normalize(vec3(0.6, 0.7, 0.4));
    vec3 fillDir = normalize(vec3(-0.5, 0.3, -0.4));
    vec3 rimDir  = normalize(vec3(-0.3, 0.5,  0.7));

    float sun  = max(dot(n, sunDir),  0.0);
    float fill = max(dot(n, fillDir), 0.0) * 0.22;
    float rim  = max(dot(n, rimDir),  0.0) * 0.14;
    float sky  = dot(n, vec3(0.0, 1.0, 0.0)) * 0.4 + 0.4;  // [0.0, 0.8]
    float light = sun * 0.75 + fill + rim + sky * 0.09 + 0.05;

    vec3 baseColor = m_HasBarkMap
        ? texture2D(m_BarkMap, texCoord).rgb * m_Diffuse.rgb
        : m_Diffuse.rgb;

    gl_FragColor = vec4(baseColor * clamp(light, 0.0, 1.0), m_Diffuse.a);
}